Punch and die unit



PUNCH AND DIE UNIT Filed Aug. 9, 1944 T, A INVENTOR IQ, 2?. JAcoB JOACl-HNH V/ /,z t ms Patente'd Apr. 17, 1945 UNITED STATES PATENT OFFICE PUNCH AND DIE UNIT Jacob Joaehlml, Snyder, N. Y., alslgnor to Bell v Aircraft Corporation, Buffalo, N. Y.

Application August a, 1944. Serial No. 548,719

4 Claims. 101. 164-124) This invention relates to machine tools, and

more particularly to improvements in die set devices for punching identically patterned holes through series of sheet metal stock pieces and the like: and more p rticularly to improvements in'punch and die units such 'as are adapted-to be interchangeably used in variously patterned setups. Thus, the invention is applicable to punch and die devices such as are presently. used in large quantities for example in connection with punching of rivet holes or the like through metal and die set of the invention mounted for operation upon a work sheet;

Fig. 2 is a-similar view showing another form of mounting for the punch and die sets oi the invention; and

Fig. 3 is a vertical section through one of the punch and die sets of the invention.

The invention is shown in the drawing to comprise animproved punch and die unit which is adapted to be mounted for operation between die blocks and rams in a variety of arrangements. For example, in Fig. 1 the die block is indicated at III to comprise any suitable stationary block preferably mounting a plurality of anchoring posts ii to which is bolted a die holder plate I4 so that the latter extends substantially parallelly to the face of the block l and in suitably spaced relation therefrom so as to be adapted to receive therebetween aplurality of the die members of the invention.

One of such die members is illustrated at it.

and as shown in Fig. 3 the die member l6 comprises a generally cylindrical body I8 and a telescopically inserted die head 28. The die body I8 is bored at its upper end to receiv in slipfitted relation therein the shank portion of the die head 20; and thus it will be understood that it will be understood that a plurality of such die elements may be readily mounted upon the die holder plate l4 in accord with any predetermined plan vie w arrangement by simply providing the die holder plate l4 to be suitably perforated to receive and properly position the shank portions of the corresponding die elements. Such perforations in the die holder plate are centered upon points corresponding to the centers of the perforations to be punched through the stock to be operated upon. The die bodie ll are diagonally counterbored as indicated at 24 into communication with the die shank receiving bore portions thereof; and the die heads are vertically bored as indicated at 25 concentrically of the die head shank portions so as to coincide exactly with the prescribed centers for the punching operation upon the stock sheets to be proc essed.

The rain of Fig. 1 is designated at to comprise any suitable movable ram device having its working surface 32 disposed parallel to the bed plate ill and carrying a plurality of suspension pins 34. A punch holder plate 38 is suitably apertured to slidably fit upon the shank portions of the pins 34 and to be thereby laterally positioned relative to the ram 30. The guide pins 34 are headed as at 38 so as to provide stirrups upon which the holder plate 36 is adapted to rest and to be stopped against accidental disassembly from the ram. The holder plate 38 mounts a plurality of punch devices which are indicated generally at 40. Each comprises a cylindrical barrel '42 (Fig. 3) having a reduced shank portion at its lower end adapted to slip-fit through a suitably apertured portion of the holder plate 36 so as to laterally position the punch unit 40 in proper punching alignment with the corresponding die unit It therebelow. A look nut 44 is provided to lock each punch unit barrel upon the guide plate 36. g

The punch cylinder 42 is vertically centrally bored to receive in free sliding relation therein a punch element 45: the lower end of the punch element 45 being adapted to protrude when the punch is hit from the cylinder 42 and to register with the bore 25 of the corresponding die head 20 for punching stock material disposed therebetween. Adjacent its upper end the cylinder 42 is slotted at opposite side portions as indicated at 48-48 to permit a 'U-shaped clip 50 to be slidably inserted to partially block the interior bore portion 52 of the cylinder. The punch 45 is provided with a shoulder portion 54 which accurately slip-fits within the cylinder bore and Thus. theplugs Ior pellets P n ed ou li si into: the] boredportions .25 of the-die heads so as ultimately our through the inclined en-' largedibored portions 1!, thereof for final disnosal thereof-i andiuponvretraction ofthe ram 3l= the springdevices55 of the punch units finit ial ly :retract the :punch devices 45 and "will .thereuponplck up the guide plate v 38 so' -as'to lift thQenflre-Dunch-set away from engages beneath the wire 50 when the unit is in assembled condition: and a compression spring 55 is mounted within the cylinder to bear upwardly against the shoulder 54 of the punch so as to normally bias the punch upwardly relative to the cylinder 42 in retracted position. Thus, it will be appreciated that subsequently to mounting a stock piece such as a metal sheet 58 between the punch and die set units, upon operation of the ram 30 so as to press it downwardly into stock sheet punching position, the lower ends of the punch cylinders 42 will initially mm the stock sheet against the corresponding top surfaces ol' the die heads. Further travel of the holder plate 36 will thereupon be blocked, but th ram 30 will be free to continue to move toward the die block due to the slip-fit connections between'the holder plate 38 and the guide pins 34. Such continued motion of the ram 30 will cause the punch devices 45 to be depressed relative toitheir corresponding cylinders 42 against the forces oftheirs'prings "so as to drive the lower punching end portions of thepunch devices through thestoclrin directions accurately aligned with the bored portions 2 of the correspend die heads ,s I I r or stock material sheets will be driven will the the punched stock so that another stock piece can l i be placed thereunder forrepetition ofthe punchingo'peration; l v

f InFig. 2 the punch and die units of the invennon: are illustrated in mounted connection upon correspondmg' holder plates "-35; the upper holder. plate being'r'nounted in a somewhat iferentmanner from the mounting thereof as lsh'own in Fig.1. 55-54 are connected to extend-upwardly from the die block II and to v support thereon the holder plate I4, as mthe manner of the support of the die holder. in-

-1.1 tended further upwardly to engage at suitably apertured portions thereof the upper holder plate 3 6 fin' 'slide fitting relation thereon, and compresysion -springs 64 are disposed-between the holder] 1 plates i436 so as to biasth'e upper holder plate 36 upwardly tonormally maintain an adequate stock sheet transfer space between the" lower end of? the punch units 40 and the upper ends of the corresponding die heads I 6. However, it will be appreciated that subsequent to mounting the stock sheet inoperative position downward movement of the ram 30 will initially displace the punch set and holder plate 36 against the action of the spring 54 until'such time as the stock sheet is firmly clamped between the punch andi'dieunits. Further travel of the ram 30 willthereupon press the punch devices 45 against the action of their coil springs in such manner asto'project the punch elements from their corresponding cylinders into stock sheet punching V relation'in directalignment with'the correspondingfiiie units, Upon release ofthe ram pressure the punch elements will initially retract, and then the-lift springs 64 are freed to operate to raise the -h'older plate itjwhereby to lift the entire Howeveni the support posts I: are ex-.

- ally stabilize the upper end of the punch element 45 relative to the punch cylinder. Thus, the lower stock perforating end portion of the punch element 45 may be safely formed to relatively slim stem-like dimensions, such as is required in connection with the punching of small size holes, because the shoulder 54 and relatively rugged upper end portion of the punch stem relieves the lower stem portion of lateral bending stresses and the like. Thus, the relatively delicately dimensioned stock perforating end portion of the punch element is protected in improved manner against stresses such as ordinarily cause excessive breakages oi punching elements of similar devices of the prior art.

Also, it will be appreciated that a particular feature and advantage of the invention resides in the fact that it is the reduced end portion of the punch cylinder er so that slip-fits into the apertured holding plate 36 for locking thereon by means of the lock nut 44; and that a single integral cylinder device carries in its lower end the relatively delicately dimensioned stock perforating endportion of the punch element '45 and guides at its upper end the more ruggedly dimensioned upper end portion of the same punch element 45. Hence, both ends of the punch element are carried by'a single rigid cylinder in lieu of art; whereby in the invention any possibility of misalignment of the punch element relative to its carrying cylinder is obviated, and whereby improved punching alignment and punch life are assured.

It will be appreciated that by reason of the specific formation and arrangement of operative parts of the punch and die elements of the mechanism, a particularly rugged and mechanically simple and fool-proof and accurately aligned punch and die set is provided; and that the elements of the invention are adapted to be eccnomically manufactured and to be easily assembled and serviced with improved facility.

Although only two forms of the invention have been shown and described in detail it will be ap parent to those skilled in the art that the inven- "tlon is not so limited but that various changes maybe made therein without departing from the spirit of the invention or the scope of the appended claims.

Iclaim: l

1. A stockpunching apparatus comprising a punch holding plate provided with an opening,

a punchunit mounted upon said punch holding plate and comprising a cylinder member having a body and a reduced end portion integral with said body and slip-fitted into said opening of said punch holding plate, means locking said reduced end cylinder portion upon said punch holding plate, said body-portion of said cylinder having a relatively' large bore and said cylinder reduced end portion having a central bore of relatively reduced dimension, a punch stem of relatively small sectional dimension at its lower end slipfltted into the bore of said cylinder reduced end portion, said punch stem having a sectionally enlarged body portion disposed within the bore .of said cylinder body portion, a coil spring disposed within said cylinder body and encompassing said enlarged stem body portion, said punch stem being formed with an enlarged shoulder accurately slip-fitting into said cylinder body bored portion and providing a bearing for said coil spring, and detachable stop means carried by said cylinder body exteriorly of said punch stem shoulder for limiting movements thereof in one direction relative to said cylinder.

2. A stock punching apparatus comprising a punch unit including a cylinder member having a relatively large body and a reduced end pore tion integral with said body, said cylinder body having a relatively large bore and said reduced end portion having a relatively small bore, a punch stem of relatively small diameter at its lower end slip-fitted into the bore of said cylinder reduced end portion, said punch stem having an enlarged diameter body portion disposed within the larger bore of said cylinder and a shoulder slip-fitting into said cylinder body bored portion for laterally guiding the upper end of said stem relative to said cylinder.

3. A stock punching apparatus comprising a holder plate provided with an opening, a punch unit mounted upon said holder plate and comprising a cylinder member having an integral reduced end portion thereof slip-fitted into said opening of said holder plate, means locking said cylinder member upon said holder plate, said cylinder having a relatively large bore at one of its ends and a relatively small bore at its reduced end, a punch stem of relatively small sectional dimension at one end slip-fitted into said small bore and a sectionally enlarged body portion disposed within said large bore, a coil spring disposed within said cylinder and encompassing said enlarged stem body portion, said punch stem being formed with a shoulder accurately slip-fitting into said cylinder large bore portion and providing a bearing for said coil spring, and detachable stop means carried by said cylinder exteriorly of said punch stem shoulder for coaction therewith to limit movements thereof in one direction relative to said cylinder, and a second holder plate provided with a second opening directionally aligned with said first opening, a die unit mounted upon said second holder plate and comprising a cylinder and a headed die block slip-fitted into said cylinder and bored in alignment with said punch stem.

4. A stock punching apparatus comprising a punch holder plate provided with an opening, a punch unit mounted upon said punch holder plate and comprising a cylinder member having a reduced end portion integral with the body of said cylinder slip-fitted into said opening of said punch holder plate, means locking said reduced end cylinder portion upon said punch holder plate, the body of said cylinder being centrally bored to relatively large diameter and said reduced cylinder end portion being centrally bored to relatively small diameter, a punch element comprising a stem-like device of relatively small diameter at its lower end accurately slip-fitted into the small bore of said cylinder reduced end portion and having a sectionally enlarged stem portion disposed within the large bore of said cylinder body, a spring disposed within said cylinder bored portion and bearing against said reduced end portion thereof, said punching element being formed with a shoulder accurately slip-fitting into said cylinder large bore portion and providing a bearing for said spring and a guide for said punching element relative to said cylinder, and detachable stop means carried by said cylinder exteriorly of said punching element shoulder for limiting movements thereof in one direction relative to said cylinder.

JACOB J OACHIMI. 

